A three-dimensional measurement of a spray droplet size distribution under microgravity was performed using pulsed laser holographic method in order to study the spray characteristics under microgravity conditions. A hologram construction system was equipped with the drop capsule of the MGLAB and free-fa]] experiments were performed. A holographic interferometric image of a fuel spray was recorded on a holographic plate and reconstructed. The reconstructed image was analyzed by image software. The droplet size and spatial distribution of every single drop were measured. The effects of the injection duration and pressure on the spray characteristics were clarified. The results are wed as fundamental data on flame propagation characteristic studies in spray compound mixtures, under microgravity conditions.
The main aspects of boiling heat transfer are exposed in the paper in view of its application in the field of space technology. The main results achieved in the experimental activity concerning boiling in microgravity, together with the areas in which further investigation and experimentation is needed, are reported in the work. A brief outline of future applications, already in the design phase, is given. An attempt is made to identify the main open problems in the field. Further experimental campaigns are expected to yield advances both in the understanding of the basic boiling mechanisms and in space heat transfer applications.